Attachment-plug for engine-cylinders.



v N. M. HOPKINS. ATTACHMENT PLUG Eon ENGINE CNLINDEES.I

APPLICATION FILED .TUNE 23, 1909.

' Patented Feb. 15,1910.

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N. M. HOPKINS.

ATTAGHMENT PLUG FOR ENGINE CYLINDERS.

APPLICATION FILED JUNE 23, 1909.

949,704. 1 Patented Feb.15,1910.

2 SHEETS-SHEET 2.

I attenua? i Patent No. v903,090, 'granted November 3 45 means similar to those'shown lin my {in the:

UNITED sTATEs PATENT l oEEICE.

NEVII, MONROE `ietOIeKINs, or WASHINGTON, DISTRICT OR COLUMBIA, AssIGNoR TO THE ELECTRIC sPEEDoMETI-:R AND DYNAMOMETER MANUFACTURING COMPANY, OF WASHINGTON, DISTRICT OF COLUMBIA, A CORPORATION OF DELAWARE.

To @IL w/wm it -my concern: e

'Be 1t known that I, NEVIL MONROE HOI nINs, .a citizen of the United States, re

siding at Washington, in the District of Co! 5 lumbia, have invented. certain new and use-y plug'for engine vcylinders and in particular to. a construction' of spark-plug, embodying` featuresfof invention applicable to sparkplugs alone, or to a combined thermo-couple and spark-plugof the kind shown in my 1908. Y l kIn the drawings,-Figure l is a sideelevation 'of my attachment; Figs." 2, 3, t and 5 are sectional elevations On thel line L -alot 2c Fig;` 10, of modified forms of the attachment.-

plug .when used as a combinedthermo-conple and spark-plug; Figs. 6- and 7,are sectional elevations ofthe devlce arranged for use as y a spark'plugonly Fig. S'is a plan' view o f the'plug with-the cover removed Fig.l 9 is a side elevation of Fig. 8, 'parts'being removed to show the manner of attaching the thermo-couple; Figs. 10 and ll-are front andv side views of the `insulating bushing and con- I nected parts; and Fig. v12'is a vertical section of a modified construction of bushing.`

The attachment plug comprises al body 2, `preferably made of steel,screw-threadedat its vlower portionto fit 'into acorresponding openingiin theengine cylinder, and threaded atitsnpper portion'to engage a corresponding screw-threadedbrass ring 3. The hollow porcelain cap "1 is secured to the ring 2 by bolts 22d passing through insulating bushivo ings 7,0 (Fig. 9.)V and nutsv71 (Fig. 1),iad ditional mits 72 On each post lservingasbinding screws for making electrical connection with the thermo-couple wires.l The thermocouple wires 10, 10 are secured .in place -lliy aPP 1- cation Serial No. 445,823, filed July 28,1908, each of these wires passing through a tube 9' A of massive C QPPer, the-.tubes passing through holes-counterbored at their bottoms, orcelai-n. bushing 5. Fitting in the socket orm'ed bythe counterbore are abutments .30, preferably formed by swaging from the metal ofl thetubes, and between these abutments and the topof the socket is v `a suitable asbestos packing or washer for fthe heat Vaway Vof the thermo-couple wires. The thermo- .-forminga partv ofthe steel body 2.

ATTACHMENT-I'LUG FOR ENGINE-CYLINDER.

`forming a lgas-tight` joint. Nuts l1 (Fig. 2), are screwed on the upperfportionof the xtubes, and serve to 'compressthe packing and Speeieation of Letters Patent." I vzttengd Feb. 154, 1910. Application filed June 23,-1909. Serial No. 503,779. i

embraced by the curved ends of-plates 25 l (Figs. 8 and 9), which at their other ends are secured as by soldering, to the screws 22, the purpose of this arrangement being to breaking the thermo-couple connecting wires 10 (Figs. 8 and 9), which are secured to the bolts 22. These lates also serve to conduct rom the metal inclosures couple wires are connected to-each other by a junction 28. I

. -The insulating bushing 5, which is prefer.- ablyof porcelain, is secured in the body 2 by means opfua-screw-threadedv ring 4, an asbestos packing 31 being interposed between this ring and a shoulder on the bushing, the bushing having its lower end rounded and engaging a corresponding rounded portion on the bod 2. This insulating bushing 5 has, in ad ition to the two -holes through whichv pass the tubes 9, 9, a third hole for receiving the electrode-wire 7',

.prevent the Ibolt-s 22 from being turned about their-'axes by the bindingnuts 72 and thus sol which constitutesv one of the spark terminals,

the other. terminal l8 being attached to-r s shown-1n Fig. 2, the electrode-wire 7 is surroundedV by a tube 6 of, silica, quartz or orcelain, ttin into a corresponding openlng inthe bushing 5, there beingl a suitable gas-tight goint- 32, `of asbestos, between the bottom fo' n v n vforming part of the wall of the bushing. The wire 7 is provided .at itsgtop with a head G4, and between the head and the top ofV the tube is interposed a washer 63. Pressino' downwardly on thev head64 of the electrode-Wire 7 is a spring 17, which bears also avainst the head of a bolt 18 held in Aplace hy' a .nut 38 (Fig. 1),-'seated in the top of the cap l. A binding nut 34' serves as a means of making electrical connection with the terminal wire 7'.' The ressure of this spring 41Zis suiiicient to tir y hold the silica tubedin` place and'lto make' a gas-tight joint between the tnb'e ,and bushing. The use ofjasiligca tubetinfthisrelation is parth silica tube and a shoulder ticularly advantageous for the reason that be made from 'some insulating material such the co-eicient of expansion of silica is practically m'l, so that the tube is not liable to be cracked owing to the wide variations in temperature to which the plug is subjected.

In Fig. 3 is `shown a modified arrangement, the silica tube 6a, in this case, extending entirely through the bushing and below the bottom thereof. Even if the porcelain bushing should crack, the electrode-wire 7 would still be protected by adequate i11- sulation, so that there would be no possibility of short-circuitinf. Between coperating shoulders on the tube and bushing is inserted an asbestos packing 33, the tube being held in place and electrical connection madeu with the Wire contained therein by the spring 17, arranged in `the same manner as described in connection with Fig.

Fi 4 shows a construction similar to that of Fig. 3 except that, in this case, the lower j end of the tube is provided with a metal cap 21 to serve as an additional means for keeping the joint gas-tight and for preventing the tube fromsplitting. Similar caps 21 may be used at the tops of thc tubes if desired.

Fig. v5 shows the tube 6b mounted ina different manner, the tube, in this case, being held up and locked to the porcelain bushing in theV following manner: The electrode-Wire 7 has near its lower end a shoulder 34 bearin against thr cap 21 on the bottom of the tu e, and at its upper -end the wire 7 is threaded to receive a nut 14. Surrounding the upper portion of the tube 6" is an insulating tube 20 bearing at its lower end on the top of the bushing 5. Between the upper end of this tube and the nut 14 is a washer 13. When the nut is screwed down, it pulls up the Wire 7 and silica tube 6b and compresses an asbestos packing 36, arranged,as shown, between coperating shoulders on the tube and bushing, thereby making a gastight joint between thel two, and also 'firmly fastening the parts together. A Contact spring 19 serves to make the necessary electrical connection to the Wire 7 and the binding screw orvbolt 18.

Figs. 6 and 7 show the plug with the therino-cou le omitted, the terminal wire 7, in Fig. 6, eing mounted in the same manner as before described in connection with Fig. ,the mounting of this electrode-wire in Fig. being the same as in Fig. 4.

26 (Fig.8), is a shunt wire by means of which the thermo-couple wires of each instrmnent can be calibrated. By adjusting the conductivity of this shunt Wire, the proportionate amount of current, transmitted to the indicating galvanometer, can be varied, as conditions mayl require.

In Fig. 12 is shown a modified construction of the bushing, which, in this case, may

as silica or quartz, this material being directly molded or cast, while plastic or molten, about the wires, tubes or limbs passing therethrough, thus insuring a gas-tight ccnnection between the wires, tubes or limbs and the bushing. In Fig. 12 the thermo-couple wires are shown as inclosed in metal tubes of good heat conductivity, these tubes being cast or embedded in the insulating material -forming the bushing so as to form a gastight connection therewith. A stuiling box 12 may be used if considered advisable.

I claim 1. A spark-plug comprising an insulating bushing, an electrodewire passing therethrough, said bushing having an opening therethrough of different diameters, a silica tube having portions corresponding with the different diameters, a` packing between the thus formed shoulders on the bushing and tube, and a spring for holding the parts in place.

2. A spark-plug coniprising an insulating bushing, an electrode-wire passing therethrouvh, said bushing having an opening thereirough of different diameters, a silica tube having portions corresponding with the different diameters, a-packing between the thus formed shoulders on the bushing and tube, a cap, and a cou'iprcssion spring between the cap and tube.

3. In combination. a itting adapted to make a gas-tight joint with an engine cylinder, 'an insulating bushing with a longitudinal opening, an insulating tube seating in said opening, a spark `electrode passing through said opening and tube, making a gas-tight joint therewith, a spring on the upper end of said tube, and an vinsulating top seating on said tit-ting compressing the spring and forcing thc seated tube in posilion.

4. A plug comprising a body, a bushing having openings therethrough, thermocouple tubes passing tlrough said openings, a cap, bolts for securing the cap to the body. and plates secured to the bolts and engaging the tubes, whereby the bolts are prevented from turning.

5. In combination, a fitting adapted to make a gas-tight joint with au engine cylinder, an insulating bushing having an opening therethrough, an electrode-wire passmg' through said opening, an insulatmg tube i surrounding said wire and extending into the bushing, a packing between the tube and bushing, and a compression springr arranged to bear on the end of the tube.

In testin'iony whereof, I ailix my signature in presence of two witnesses.

NEVIL MONROE HOPKINS. lVitnesses:

J. H. Bluonnxsrmx, N. P. LEONARD. 

